Tobias Achterberg
-
Gurobi Staff
- 合計アクティビティ 108
- 前回のアクティビティ
- メンバー登録日
- フォロー 0ユーザー
- フォロワー 1ユーザー
- 投票 0
- サブスクリプション 0
コメント
Tobias Achterbergによる最近のアクティビティ-
Just to make sure I understand it correctly: you get these very strange values like 1e+69 or 1e-310 in the model, even though you never added those coefficients in your Python program? My guess is ...
-
In order to count the number of non-zeros, you would typically introduce binary variables that indicate whether a given variable is 0 or not. So, if you have integer variables x1,...,xn, then you w...
-
Your expectations are correct. An overall model status of OPTIMAL means that there was at least one feasible scenario, but there can also be infeasible scenarios. Whether a particular scenario is f...
-
1) Correct, you cannot set variable attributes in a callback. But you can produce the cut "x <= 0" and add this as a user cut. Internally, this will then be converted into a bound change. 2) Yes, i...
-
Yes, it is not possible to pass an LP basis to a MIP solve. This is mostly because the MIP preprocessing would usually invalidate any warm start basis anyways, because most of the MIP preprocessing...
-
I would like to investigate. Could you please send me - your original model as *.mps file, - your MIP start as *.mst file or *.sol file, and - your modified model with bounds fixed to the MIP start...
-
Where do these log files come from? From the feasRelax model?
-
I don't understand why you want to use a callback function here. Inside a callback, you cannot modify or extend the model that you are currently solving. It sounds more like you want to have an out...
-
That is not a particularly large model. But it is hard to say how you can improve your model without knowing anything about it. Would it be possible to send me your *.mps file? I would like to take...
-
Yes, using an indicator is the right way to go. And it is very easy, you just need to invert the direction of the indicator. Instead of f_r > 0 -> i_r = 1 you would enforce i_r = 0 -> f_r <= 0 This...